A commonly assigned prior patent application Ser. No. 837,198 filed Sept. 28, 1977, (now abandoned in favor of application Ser. No. 058,869 filed July 19, 1979, also commonly owned), and corresponding to German Application P 26 47 167.0 filed Oct. 19, 1976, illustrates arrangements similar to the first and second figures herein. Methods are known, for example, from the "Encyclopedia of Medical Radiology", Vol. 1, Part 2, 1965, Pages 203 to 212 wherein tomograms are produced with x-rays or similarly penetrating radiation by scanning of the subject under examination with a beam of rays emanating from a source and wherein the beam which issues from the subject under examination acts upon a recording device, the source and recording device being moved in unison to bring about the scanning of the desired bodily layer.
As is known, in order to produce tomograms with x-rays, at least two parts of the required recording arrangement, i.e., radiation source, examination subject, and recording device, are moved relative to one another. Depending upon the methods and recording elements employed, the patient is, in most instances, kept motionless in medical diagnosis, so that a movement of the x-ray tube and the photographic cassette takes place. However, this necessitates the acceleration and deceleration of relatively large masses, which is expensive because it is desirable to accomplish this in as short a period of time as possible during a radiographic procedure.
However, with respect to the conventional tomographic procedure, the decisive factor is the process of initiating relative motion, because this determines the time requirement, particularly in the case of only a one sided-operating cycle. In the case of conventional apparatus for displayng linear layers, the shortest photographic times have proved to be of the order of 600 milliseconds. More rapid recording cycles are only possible at considerable expense.
However, in so doing, only a reduction by half of the shortest tomographic times which are otherwise possible can be achieved as a rule. In order to photograph moving organs, such as the heart, tomographic times of 80 msec would have to be obtained. Taking into consideration the movement sequences of individual parts of the heart within the heart phase, moreover, a tomographic time of 20 msec appears desirable. Rapid movements such as this cannot be obtained with the mechanical means presently available.